While it may be tempting to argue that time is not relative, that it is a finite and completely inexorable, doing so also goes against that which some of the brightest minds of modern history have taught us. It is a fact that the majority of experts in the world today, people with a deep, thorough knowledge of physics and mathematics, believe wholeheartedly in the fact that time is relative. Why?
Well, to begin with, when scientists use the term "relative" they don't mean "subjective." Those concepts, within the frame of this argument, are completely different. The fact that time's flow is subjective is obvious to each of us. What person hasn't sat in a classroom at some point, been bored, and felt as if time were perceptibly slowing down? That is a direct result of time's subjective nature. We each intuit the passage of time differently, and therefore our perception of it can vary greatly. Some time seems to "fly by" while other seems to "crawl." This is because, for us, that time was processed in our brain in a specific manner that made it seem to be different from other time.
Such perception differences between individuals is not, however, the basis of the argument that time is relative. Instead, the argument is that time is relative to motion. This is not, in fact, even really an argument or theory. It has been proven. Stop watches and clocks that are placed in jet aircraft moving at supersonic speeds run more slowly than ones on the ground. This has been demonstrated time and time again.
The question, then, is why? Why does time slow due to speed of motion? Well, it all has to do with the proofs of Albert Einstein's theory of relativity. Essentially, without getting too in-depth, Einstein's theory mathematically proved a number of amazing concepts. The primary one that concerns this argument, however, is that time is relative to speed. And, theoretically speaking, his theory of relativity also proved that time ceases at light speed. In other words, if human beings could build a machine that could reach the speed of light, Einstein posited that time would stand still for the people aboard it.
While both the full truth of Einstein's theory, and the ability of mankind to build such a machine, still lie in question, one thing does not: time is relative. Everything that people have been able to scientifically demonstrate supports this idea. The greatest minds in physics all support it without equivocation. To argue otherwise is to take on the minds of men like Albert Einstein, Robert Oppenheimer, and Niels Bohr. Those are also some of the men who invented the atomic bomb. So, when it comes to matters of physics, it might be wise for the average person to yield the floor.